Extension of linear isotherm regularity to long chain primary, secondary and tertiary alcohols, ketones and 1-carboxylic acids by group contribution method

0 d In this work, the group contribution approach has been used in combination with the linear isotherm regularity (LIR) equation of state to stimate pvT properties of primary, secondary and tertiary alcohols, ketones and 1-carboxylic acid. In addition, the isothermal compressibility nd thermal expansion coefficient of these compounds have been predicted. We assume each of these organic compounds as a hypothetical ixture of methyl, methylene and a functional group, in which the interaction potential of each pair is assumed to be the average effective air potential. Then, the LIR equation of state (EOS) has been extended to such a hypothetical mixture. Three basic compounds, namely ropane, n-butane and cyclohexane, are used to obtain the contribution of methyl and methylene groups in the EOS parameters and also other ppropriate compounds are used to obtain the contribution of the functional groups, such as: 1-pentanol for the contribution of CH2OH, -pentanol for the contribution of CHOH, 2-methyl-2-propanol (t-BuOH) for the contribution of − | C | OH, 2-pentanon for the contribution f C O and 1-pentanoic acid for the contribution of COOH groups. The calculated EOS parameters along with the modified EOS are then sed to calculate the density of different compounds at different pressures and temperatures with the average percentage error less than 1.2. lso, the thermal expansion coefficient at different temperatures and isothermal compressibility at different pressures are calculated for some ydrocarbons with absolute percent deviation less than 1.0. 2005 Elsevier B.V. All rights reserved.